Mott-Schottky Heterojunction Modulating Iron-Vanadium Oxide for High-Performance Aqueous Zinc Battery Cathodes

Vanadium-based oxides have garnered significant attention for aqueous zinc batteries (AZBs), whereas sluggish Zn²⁺ diffusion and structural collapse remain major challenges in achieving high-performance cathodes. Herein, different structures of iron-vanadium oxides were fabricated by modulating the amount of vanadium content. It is found that the porous Mott-Schottky heterojunction composed of Fe_0.12V₂O₅ and Fe₂V₄O₁₃ mixed phase was used to construct a self-generated FeVO-5 structure, which could lower the diffusion barrier and improve the electron transport derived from the formed built-in electric field at the interface, showing faster reaction kinetics and improved capacity compared with the singe-phase FeVO-1. Surprisingly, the FeVO-5 cathode delivers an impressive capacity of up to 431 mAh g^-1 at 0.6 A g^-1, excellent rate capability (252.3 mAh g^-1, 80 A g^-1), and superior long-term cycling performance (95% capacity retention over 12 000 cycles at 40 A g^-1). This work presents a reasonable strategy for engineering heterostructure materials for AZB application.